std.debug: Add unwind support for serenity

Author: linusg

lib/std/debug.zig

@@ -1276,6 +1276,7 @@ pub const have_segfault_handling_support = switch (native_os) {
     .windows,
     .freebsd,
     .openbsd,
+    .serenity,
     => true,
 
     else => false,
@@ -1359,7 +1360,7 @@ fn handleSegfaultPosix(sig: i32, info: *const posix.siginfo_t, ctx_ptr: ?*anyopa
         }
         const addr: usize = switch (native_os) {
             .linux => @intFromPtr(info.fields.sigfault.addr),
-            .freebsd, .macos => @intFromPtr(info.addr),
+            .freebsd, .macos, .serenity => @intFromPtr(info.addr),
             .netbsd => @intFromPtr(info.info.reason.fault.addr),
             .openbsd => @intFromPtr(info.data.fault.addr),
             .solaris, .illumos => @intFromPtr(info.reason.fault.addr),

lib/std/debug/SelfInfo/Elf.zig

@@ -114,6 +114,11 @@ pub const can_unwind: bool = s: {
             .x86,
             .x86_64,
         },
+        .serenity => &.{
+            .x86_64,
+            .aarch64,
+            .riscv64,
+        },
         else => unreachable,
     };
     for (archs) |a| {

lib/std/debug/cpu_context.zig

@@ -57,7 +57,7 @@ pub fn fromPosixSignalContext(ctx_ptr: ?*const anyopaque) ?Native {
                 .r15 = uc.mcontext.gregs[std.posix.REG.R15],
                 .rip = uc.mcontext.gregs[std.posix.REG.RIP],
             }) },
-            .freebsd => .{ .gprs = .init(.{
+            .freebsd, .serenity => .{ .gprs = .init(.{
                 .rax = uc.mcontext.rax,
                 .rdx = uc.mcontext.rdx,
                 .rcx = uc.mcontext.rcx,
@@ -174,6 +174,11 @@ pub fn fromPosixSignalContext(ctx_ptr: ?*const anyopaque) ?Native {
                 .sp = uc.mcontext.sp,
                 .pc = uc.mcontext.pc,
             },
+            .serenity => .{
+                .x = uc.mcontext.x,
+                .sp = uc.mcontext.sp,
+                .pc = uc.mcontext.pc,
+            },
             else => null,
         },
         .loongarch64 => switch (builtin.os.tag) {
@@ -188,6 +193,10 @@ pub fn fromPosixSignalContext(ctx_ptr: ?*const anyopaque) ?Native {
                 .r = [1]usize{0} ++ uc.mcontext.gregs[1..].*, // r0 position is used for pc; replace with zero
                 .pc = uc.mcontext.gregs[0],
             },
+            .serenity => if (native_arch == .riscv32) null else .{
+                .r = [1]u64{0} ++ uc.mcontext.x,
+                .pc = uc.mcontext.pc,
+            },
             else => null,
         },
         .s390x => switch (builtin.os.tag) {